engleski

Oral cadmium exposure during rat pregnancy: assessment of transplacental micronutrient transport and steroidogenesis at term

Diet is the main source of cadmium exposure. Gastrointestinal absorption increases during pregnancy. Cadmium accumulated in the placenta may interfere with nutrient transport to the foetus. Data on the potential of cadmium to act as a steroid disruptor of pregnancy are limited. We evaluated the effects of oral cadmium exposure during pregnancy on placental function in micronutrient transfer to the foetus and steroidogenesis in Wistar rats (regular 4-day cyclers) that mated with unexposed males. Pregnant rats were randomly assigned to a cadmium group exposed orally to 50 mg Cd/L (50 ppm ; as CdCl2xH2O dissolved in demineralised water), ca. 7.5 mg Cd/kg b. wt. a day, during 20 days of gestation and control (supplied with demineralised water). Non- pregnant rats were treated under the same experimental conditions. On day 20, all of the rats were euthanized and samples were taken for element analyses (by ET-AAS). Progesterone and testosterone were measured in serum and placenta- derived samples (by IEMA and/or ELISA). In the exposed rats, cadmium increased in blood and organs, more in pregnant rats, and in placenta and foetus whereas zinc increased in liver. Iron decreased in maternal organs and in foetus, whereas zinc decreased in maternal kidney and placenta. Liver copper was lower and kidney copper higher in all pregnant vs non-pregnant rats. Steroids in serum and placenta did not change. In conclusion, oral cadmium exposure during rat pregnancy does not affect progesterone and testosterone at term. Transplacental iron and zinc handover are disrupted, which may put at risk maintenance of foetal nutrition and viability.

cadmium; pregnancy; placenta; foetus; iron; zinc; copper; progesterone; testosterone; rats

nije evidentirano